I'm working on a small robotics project where I need to enable my old phone (Nokia 5230, shows up as USB Serial port on Windows but USB cable is straight-through) to talk to an Arduino UNO R3 (doesn't support USB Host mode natively).
My idea is wiring together the USB cable for the phone and the USB end of the adapter and wire the DATA/CLOCK port out of the PS/2 socket to the Arduino and communicate over USB serially.
Essentially, the phone will act same as a PS/2 keyboard connected does to the Arduino.
Sorry if my answer is lacking on original research, I am just inquiring if it's feasible (and some general advice) so I can start reading more on it in depth.
ps: With active I mean, Windows shows the adapter as composite USB device (with nothing connected at the PS/2 ports) and there is a circuit inside with some capacitors and a big epoxy blob on it.